fix: await applyAction and goto

[GitRowin]

Here is a simple form with a button that gets disabled while the form is being submitted:

<form
  method="post"
  use:enhance={() => {
    sending = true;
    return async ({ update }) => {
      await update();
      sending = false;
    };
  }}
>
  <div>
    <button disabled={sending}>{sending ? "Sending..." : "Send"}</button>
  </div>
</form>

If the server responds with a redirect, I expect the button to stay on "Sending..." until the other page shows up. Unfortunately, this is not what happens right now: .

And here is what it looks like after these changes: .

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🦋 Changeset detected

Latest commit: d23e70b

The changes in this PR will be included in the next version bump.

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[Rich-Harris]

preview: https://svelte-dev-git-preview-kit-13032-svelte.vercel.app/

this is an automated message

[dummdidumm]

I think this makes sense. The question is what exactly happens if the redirect happens and then the code from the previos page runs. This could possibly also cause problems because it tries to change elements that are no longer there.